Orbital action over Hesiod
|side2= |commanders1= Admiral Linda Nagata |commanders2= Unknown Covenant Fleetmaster Thel 'Vadam |forces1= UNSC 3rd Fleet, 23 Librae Defense Force *1 Marathon-class Cruiser *2 Destroyers *4 Frigates *3 Light Patrol Craft |forces2= Fleet of Glorious Interdiction (Detachment) *4 CCS-class Battlecruisers *1 CPV-class Destroyer *4 Trans-light Kig-Yar Raiders |casual1= Heavy *1 cruiser lost. *1 destroyer lost, 1 destroyer moderately damaged. *3 frigates lost, 1 frigate heavily damaged. *3 light patrol craft lost *Approximately 3,000 crewmen killed or missing |casual2= Light *1 cruiser lost, 1 cruiser heavily damaged. *1 CPV-class destroyer heavily damaged, later scuttled. *2 Kig-Yar raiders lost. |conc = Battle of 23 Librae System}} This orbital action was a naval engagement that took place in the outer-colonies during the Battle of the in December, 2528. During the action, the UNSC and the Covenant Empire skirmished in orbit above the gas-giant . Background At 0430 (MPT) on December 20, 2528, the long range sensor station ST-3 detected a number of large objects just beyond the extreme perimeter of the 23 Librae System. A silhouette analysis identified the objects to be a number of Covenant capital ships on a slow approach vector for the main celestial bodies of the system. This placed the system's largest population center, the colony world of Madrigal, at great risk. At 0451 hours, news of a Covenant fleet's arrival reached the desk of UNSC Admiral Linda Nagata, the planetary administration of Madrigal, and the chief of staff for Madrigal's planetary militia. The order was issued to begin an evacuation of the planet, abandon all mining facilities around the system, and to activate the UNSC planetary garrison in order to prepare a ground defense in the event of a Covenant landing operation. Additionally, Admiral Nagata mobilized the 23 Librae Defense fleet and all UNSC naval personnel in the system were immediately recalled to their duty ships. The defense fleet comprised of numerous vessels detached from the UNSC 3rd Fleet as well as a number of aging in-system patrol craft offered to the admiral at the last second by the planetary administration; the flagship of the formation was the Marathon-class cruiser UNSC Kershaw ''(CA-177).'' By 0600 hours, the defense fleet had finished all preparations, left orbit around Madrigal, and sortied out to intercept the Covenant fleet on its approach to the interior of the system. Action The defense group began their sortie with an orbital slingshot maneuver around the planet Madrigal. Benefiting from the additional momentum as they left the pattern, the defense group set a direct course for the Covenant fleet, which was only two hours away under conventional power. The UNSC had very little intelligence on the range of Covenant sensors at this point in the Human-Covenant War so Admiral Nagata ordered her ships to make for silent running in order to minimize their detection signatures. It was around 0620 hours that Nagata's staff noticed the three patrol craft sent by Madrigal's planetary administration had been illegally refitted by the colony with a number of TRX-23 heavy mass-drivers. These mass-drivers had been typically used only by local mining operations to break up large asteroids and typically not for combat operations. Admiral Nagata made a note of this in her official log but allowed the colony's patrol ships to continue on as a part of her formation. At approximately 0640 hours the defense group neared Hesiod and crossed through the outer boundaries of the gas giant's Lagrangian positioned asteroid field. It was at this time that the Covenant battlegroup entered the optimal sensor range of ST-3 . The station forwarded a databurst to Nagata outlining the position and an approximate composition of the Covenant fleet.What the station had detected within the Covenant formation was 4 Covenant CCS-class battlecruisers, a CPV-class heavy destroyer, and an unidentifiable number of small craft. Admiral Nagata's force was placed at a severe disadvantage due to the discrepancy in tonnage between the two formations. At 0643 hours, the Covenant commander detected the Human presence within the system and adjusted the Covenant formation's course toward Madrigal. Noting that the Covenant vessels were headed straight toward a population center, Nagata halted her flagship Kershaw ''and the destroyers ''Dartmouth ''and ''Cread within the cover of Hesiod's asteroid field. While the ships jockeyed into position, Nagata ordered her four frigates'' into the open space between the asteroid ring and Hesiod itself, and the three colony patrol ships to the asteroids on far side of the gas-giant. This positioning gave Nagata a 360 degree field of view around Hesiod for her formation's sensors. When the formation entered position around 0650, Admiral Nagata ordered her frigates to transmit nonsensical information into deep space using an encrypted databurst in order to make the frigates' positions known to the Covenant fleet. Interestingly, the information the databursts contained was simply the ''Kershaw's mess menu and schedule for the year. Upon noticing the databurst moments after it began, the Covenant fleet immediately adjusted course for the defense fleet's location. At 0659 hours, the local sensor platforms ST-1 and ST-2 went dark. Moments later, ST-3 and ST-4 went silent as well. Unknown to Admiral Nagata, the stations had been destroyed at close range by 4 Kig-Yar spacecraft which had executed coordinated pinpoint in-system jumps in order to catch the stations by surprise. The destruction of all of the system's long range sensor networks left Nagata and the UNSC mostly blind to all actions of the Covenant fleet until they entered sensor range of the UNSC formation. Around ten minutes after the loss of the sensor networks the main Covenant force executed a pinpoint slipspace jump, appearing above the northern pole of Hesiod. The Covenant fleet had positioned itself high above Nagata's position and had in turn forced the Kershaw, Cread, ''and ''Dartmouth ''to maneuver in order to align targeting solutions for their primary kinetic weapons. At this time it seemed that the Covenant force hadn't noticed Nagata's ships hidden in the asteroids as the Covenant force commander elected to target Nagata's frigates, which sat stationary and exposed in the space near Hesiod's equator. Before the cruiser ''Kershaw, ''and the destroyers Cread and Dartmouth ''could align firing solutions for their primary cannons the Covenant ships launched a spread of plasma torpedoes toward Nagata's frigates. Aftermath Though the local naval forces of the UNSC were largely decimated, the engagement lent precious time to the hundreds of civilian and in-system freighters which carried close to a million civilians away from planet Madrigal. The United Nations Space Command faced extreme criticism after withdrawing from the system after the planetary defenses began to fall when Covenant forces sent ground forces to Madrigal. Many leaders within the UEG colonial assembly voiced outrage toward the UNSC admiralty after the Fall of Madrigal, but the UNSC Navy insisted that there was nothing more that could have done do to delay the destruction of the colony any further. In order to mask their electronic signatures from the Covenant, the evacuation fleet concealed themselves deep in the system's surrounding Oort cloud. The refugee flotilla hid for weeks until the system was void of all Covenant activity then established a settlement among the evacuated mining facilities hidden within the Lagrangian asteroid cluster around Hesiod. The settlement slowly began to flourish, unknown for years to the UNSC. This settlement came to be known as Order of Battle